Fluorescent dyes are optimized for labeling proteins, in particular, antibodies. These dyes are bright, photostable and have minimal quenching on proteins. They can be well excited by the major laser lines of fluorescence instruments (e.g., 350, 405, 488, 555 and 633 nm). Fluorescent 555 dyes have fluorescence excitation and emission maxima of ~550 nm and ~570 nm respectively. Fluorescent 555 family has the spectral properties essentially identical to those of Cy3? (Cy3? is the trademark of GE Healthcare). Compared to Cy3 probes Fluorescent 555 family has much stronger fluorescence and higher photostability. Their fluorescence is pH-independent from pH 3 to 11. These spectral characteristics make this new dye family a superior alternative to Cy3?. Fluorescent 555 family has become an excellent replacement for Cy3? and Alexa Fluor? 555 labeling dye (Cy3? and Alexa Fluor? are the trademark of Invitrogen and GE Health Care). Fluorescent 555 maleimide is reasonably stable and shows good reactivity and selectivity with thiol group.
Fluorescent 555 maleimide
H303, H313, H333
HeLa cells were stained with mouse anti-tubulin.
R20, R21, R22
Excitation (nm):557, Emission (nm):570, Extinction coefficient (cm-1 M-1):100000, Quantum yield:0.64, Correction factor (260 nm):0.23, Correction factor (280 nm):0.14